Method of making case-hardening material.



PATENT oi nicn.

noon nonman. or nnonwoonrnnnsrtvanili, assidnoa r0 Rom/ran CHEMICALCOMPANY, A CORPORATION or rnnnsrtvanrai METHOD OF MAKING CASE-HARDENENGMATERIAL.

ll,7,i53. No Drawing.

To all whom it may concern Be it known that I, Hncn RODMAN, a citizen ofthe United States, and a resident of Edgewood, in the county ofAllegheny and State of Pennsylvania, have made a new and usefulInvention in hlethods of Making; (use-Hardening; Material, of which thefollowing is :i specification.

This invention relates to improved methods of manufacturing carbonizingmaterials for dry packing.

Many carbonizing materials and purely mechanical mixtures which aresatisfactory chemically are of little commercial value because of beingfinely powdered. While admitting of intimate mixing, this finelypowdered condition of the material makes difficult handling, favorsseparation of particles of different size and density and greatly lowersthe thermal conductivity. l have discovered that these troubles may beovercome and valuable material made from dusts which are now frequentlyWasted by fixing finely powdered materials in small masses or pebbles,preferably with a binding material, so that any coking materialcontained will coke internally only and so that the masses or pebbleswill not disintegrate or deform or sinter together when highly heated.By coking I mean the property of caking o'r coking to a solid charpossessed by such carbonaceous materials as leather dust and crushedcoking coal when highly heated; and by coking internally only I mean theproperty possessed by coking material of coking and binding the materialwithin the surface of properly constructed small masses or pebbleswithout deformation or disintegration of these masses and with outsinterin'g or coking; to adjacent masses. By small masses or pebbles Imean rigid masses of any shape but preferably rounded masses which maybe one-sixteentl'i or one-quarter inch in diameter.

My preferred method of carrying out my invention is to mix one hundred.parts of timely powdered coking coal with ten parts of sodium carbonateand twenty parts of calcium carbonate. moisten the dry mixture with asolution of molasses in water, force the moist mass through a screen.having; four wires to the linear inch and then tumble in revolvingbarrels occasionally addingsome dry mixture till rounded and compactedinto firm pebbles.

Specification of Letters PTRTJLU t.

Application filed April 25, 1913.

' screens ha vi Undersize and oversize peb- Patented @ctnfELiQiS.

Serial No. 763.527.

bles are then screened out and returned to the miners while pebbles ofapproved sizes are dried with -gentle heat or preferably coked inrevolving kilns heated to about fifteen hundred degrees (1500")Fahrenheit. The molasses and carbonates react to form a bond whichallows the coal to COk'QllllLEP- nally but prevents any deformation ordisii'itegratiou of individual pebbles or adherence to adjacent pebbles.

Another method is to mix one hundred parts of finely powdered cokingcoal with one hundred parts of Portland cement and fifty parts of bariumcarbonate, moisten the dry mixture with water or molasses and Water andthen press the mass into molds to dry. hen set and hard the large massesare crushed to the size desired, the undersize being returned to themixers and mixed with fresh material for resetting. When heated, thismaterial will coke internally only, making a hard, strong; substance.but will not deform-or adhere to adjacent small masses.

Other binding material. as glucose or starch or asphaltum, may form theinitial bond, the internally coking coal forming the final and strongbond and other methods be employed in forming the small masses, theessential condition being that the small masses be so constructedand'bound that the coal will coke internally only. I have found that:the tendency of the pebbles to break down and coke externally isinfluenced somewhat by the character of the coal and the strength of thetemporary bond, but mainly by the fineness of the coal particle. Coalground to ass a screen having two hundred wires to tlie linear inch. issatisfactory in most cases and coal that will just pass one hundredwires to the linear inch wi l serve where strong bonding is employed.

I do not wish to be limited to the use of screens Within the limitsmentioned, for example, with certain kinds of coal l may utilize screenshaving as few asafiity wires to the linear inch.

- Where the pebbles are cokcd in rotating kilns the coal may be coarserthan when coking is done in stationary pots, as usual in carbonizingoperations.

I have made satisfactory material by tumbling a mixture of one hundredparts of powdered charcoal and forty parts of balid rium carbonate withenough molten asphaltum or coal tar to convert it into firm pebbles. When heated these are bonded by the cokin asphaltum or tar but will notcoke or adhere to each other if the pebbles have been tumbled till firmand strong.

it have moistened a mixture of equal parts of powdered charcoal andPortland cement and then pebbled this by tumbling in revolving barrelsor else allowed it to set in large masses which were subsequentlycrushed as already described. When heated to a carbonizing temperaturethese will not disintegrate or deform but the cement bondis muchweakened by the heat and the material is not so satisfactory as where acoking material is used to make a solid, strong bond, the small massesbeing so made that the col;- ing materialwill coke internally only.

What i claim is:

1. The method of adapting finely divided material for use as carbonizingmaterial, which consists in mixing the material with a binding agent andforming small masses which will maintain their identities when heated.

2. The method of adapting finely divided material, containing cokingmaterial, for use as carbonizing material which consists in mixing thematerial with a binding agent and forming small masses which willmaintain their identities when heated.

3. The method of adapting finely divided material, containing cokingcoal, for use as carbonizing material, which consists in mixing thematerial with a binding agent and forming small masses which willmaintain their indentities when heated' 4. The method of adapting finelydivided material for use as carbonizing material, which consists inmixing it with a binding agent and forming small masses which will cokeinternally only.

The method of adapting finely divided material, containing cokingmaterial, for use as carbonizing material, which consists in mixing itwith a binding agent and forming small masses which will coke internallyonly. l'

6. The method of adapting finely dii'ided material, containing cokingcoal, for use as carbonizing material, which consists in mixing it witha binding agent and forming small masses which will coke internallyonly.

7. The method of adapting finely divided material for use as carbonizingmaterial, which consists in mixing it with a binding liquid and tumblingto form small rounded pebbles which will maintain their identities whenheated.

8. The method of adapting finely divided material, containing cokingmaterial,

for use as carboniz'ing material, which conmaterial which consists infashioning finely sists in mixing it with a binding liquid and oraiestumbling to form small rounded pebbles which will maintain theiridentities when heated.

9. The method of adapting finely divided material, containing cokingcoal, for use as carbonizing material, which consists in mixing it witha binding liquid and tumbling to form small rounded pebbles which willmaintain their identities when heated.

10. The method of adapting finely divided material for dry packing foruse as carbonizing material, which consists in mixing it with a bindingagent and separating the resulting mass into relatively small masses ofappreciable size.

11. The method of adapting finely divided material for dry packing,containing coking material, for use as carbonizii'ig material, whichconsists in mixing it with a binding agent. and separating the resultingmass into relatively small masses of appreciable size.-

12. The method of adapting finely divided material for dry packing,containing coking coal, for use as carbonizing material, which consistsin mixing it with a binding agent and separating the resultant mass intorelatively small masses of appreciable size.

13. The method. of adapting finely di vided material for use ascarbonizing material which consists in mixing it with a binding agentand then forming small masses therefrom, and then heating the smallmasses to coke them internally only.

14. The method of adapting finely divided material, containing cokingmaterial, for use as carbonizing material, which consists in mixing itwith a binding agent and then forming small masses therefrom, and

then heating these small masses to coke them internally only.

15. The method of adapting finely divided material, containing cokingcoal, for use as carbonizing material, which consists in mixing it witha binding agent and then forming small masses therefrom, and thenheating'these small masses to coke them internally only.

16. The method of preparing carbonizing material which consists infashioning finely divided material into substantially smoothsurfacedpebbles.

17. The method of preparing carbonizing material which consists infashioning finely divided material into substantiall smoothsurfacedpebbles and in then app ying heat thereto.

18. The method of preparing carbonizing material which consists infashioning finely divided material into substantially smoothsurfacedpebbles and in then coking said pebbles.

19. The method of preparing carbonizing divided material intosubstantially smoothsurfaced pebbles and applying heat thereto.

20. The method of preparing carbonizing material which consists infashioning finely divided material, containing coking material, intosubstantially smooth-surfaced pebbles and applying heat thereto.

21. The method of preparing carbonizing material which consists infashioning finely divided material, containing coking coal,

into substantially smooth-surfaced pebblesand applying heat thereto.

22. The method of adapting finely divided material for use ascarbonizing material Whichconsists in mixing the material with a tackybinding agent and forming small masses which will maintain theiridentities when heated. Y

23. The method of adapting finely divided material for use ascarbonizing material which consists in mixing the material with a tackybinding agent, then forming small masses therefrom, and in then cokingsaid small masses.

24:. The method of adapting finely divided material for use ascarbonizing material which consists in mixing it with a binding liquidand tumbling to form small rilmnded pebbles, and then coking said pebbes.

25. The method of adapting finely divided material for use ascarbonizing material which consists in mixing the material with abinding agent such as molasses, and

then forming small masses which will maintain their identities whenheated.

In testimony whereof, I have hereunto subscribed my name this 23rd dayof April, 1913.

o. w. MOGHEE, ADA Bonus.

